
<html>
  <body>

    <div>
      dd
    </div>

  </body>
  <style>
    div{
        width: 200px;
        height: 200px;
        background-color: rgb(255, 156, 156);
        transition-property: width,height;
        transition-duration: 3s;
        transition-timing-function: ease-in;
    }
    div:hover{
        width: 300px;
        height: 300px;
    }
</style>
</html>